Method of and means for treating sewage



Aug. 30, 1938.

R. E. BRIGGS 2,128,347

METHOD OF AND MEANS FOR TREATING SEWAGE ,Filed Dec. 24, 1935 2Sheets-Sheet l 4 l /NVENTOR: o n ROBERT E. BRIGGS, N i l BY Arr'x Aug.30, 1938. R. E. BRIGGS METHOD OF AND MEANS FOR TREATING SEWAGE 2Sheets-Sheet 2 Filed Dec. 24, 1935 [/VVE/XTOF? ROBERT E. BRIGGS,

Patented Aug. 30, 1938 METHOD OF AND MEANS FOR, TREATING SEWAGE RobertE. Briggs, Columbus, Ohio, assignor to The Jeffrey Manufacturing of OhioCompany, a. corporation Application December 24, 1935, Serial No. 56,015

5 Claims.

This invention relates to a method and means,

for treating sewage in is screened of large parti tervals, thescreenings b 5 with water to reduce th which a sewage channel cles atpredetermined ineing mechanically ground em to a pulp after whichtomatic means, vision.

thus requiring no direct superhereinafter, the novel being set forth inthe In the accompanyin Fig. 1 is a side elevation proved screen andassociated ing my invention, channel, illustrate Fig. 2 is an en of Fig.1 showin tion;

Fig. 3 is a detailed switch mechanism al view of the imapparatuscomprisshown in relation to -a sewage d in longitudinal section.

01 upstream view of the device g. the channel in transverse secview ofthe rake operated and taken on line 3-3 of Fig.

1, looking in the direction of the arrows;

Fig. 4 is an enl and rake cleaning arged detail mechanism;

view of the rake Fig. 5 is. a view similar to Fig. 4 withthe rakecleaningmechanism sition;

Fig. 6 is a view on Fig. 7 is a wiring In the operation lines 6 6 of Fiin the direction of the arrows; and

diagram of my system.

of a sewage treatment plant moved to rake cleaning pog. looking it isdesirable to screen the raw sewage, thereby to remove large p articlesof material which, if

not removed, would tend to disrupt the proper operation of the plant,for example, by becoming clogged in pumps, thus rendering the pumpsinoperative.

The accumulation raking the screens pr problem. In the process of atedmaterial is ground into a pulp and returned to the sewage strea size ofthe material moved intermittently charged into a grind of materialderived from esents a somewhat serious my invention this acm. Due to thereduced it may be easily handled by the pumps and settled out with thesludge in in which the tanks of the sewage treatmaterial is refrom thescreen and dis to which is fed a' stream of water to aid in the grindingandreduction of the accumulated material.

It is also preferred that the entire system be made automatic so thatcontinuous attention is not.required, and the system will operate in asatisfactory manner at all times. The cycle of operation of theautomatic system will be described in detail hereinafter. Referringparticularly to Figs. 1 and 2, there is seen mechanism for carrying outmy method, which mechanism also comprises my invention. A sewage troughor channel It) is provided which may be made of poured concrete andcomprises side walls II, I l, bottom l2 and top wall I3; The top wall l3may also comprise a floor of the building which houses the screenequipment.

Extending downwardly into the channel 10 is a screen M which may be ofthe construction disclosed'and claimed in my United States Patent screenscraper, Serial No.

740,159, filed Au 6, 1934. Briefly described,

gust 1 this screen comprises a grinder 2| driven from a Associated withthe screen I 4 is a rake operated mechanism 23 which, in general, is ofthe ,548 for a Material handling apparatus, filed December -8, 1933.Said rake opera ating mechanism 23 comprises a pair of substantiallyU'shaped guides 24, 24, each of which comprise a pair of parallel spacedplates 25, 25 (see Fig. 3) which are rigidly plate 26, by integralflanges.

Adjacent the open and top portion of each of nism 29 from a motor 30.mechanism 23 is rigidly mounted upon the top wall or iloor I3 by a frame3| formed of appro-' priate angle members. The motor 30 may be mountedupon a bracket 32 forming a portion of the frame 3|. Each of theU-shaped uid 24, 24 provides g as The rake operating a guide means foran endless 5 attached to a flat side chain 33 which is adapted to traveldown into the channel W and into the sewage which flows in said channelin the direction indicated by. the arrow 34. It is to be noted that dueto the particular U-shaped guides 24, 24 there is a complete absence ofany guiding 'and supporting sprockets within the sewage stream.

Extendingbetween the chains 33 I provide a rake mechanism 35 adapted toremove from the screen l4 the accumulated refuse orsewage, and todischarge it into the hopper 26. As illustrated in the drawings there isone such rake mechanism 35 though the number may be increased, ifdesired.

Said rake mechanism 35 comprises a pair of plates 36, 36 (Fig. 6) whichare rigidly attached to links of the chains 33, 33 as by brackets 31,31. Each of said plates 36, 36 is provided with an inwardly extendingstop 38 and with an inwardly extending bolt 39 adapted to receive a nut46. Pivotally mounted upon each of said bolts 39 is a lever 4|.-Extending between the two levers 4| is a rake plate 42 provided withteeth 43. Also pivoted upon each of the bolts 39 is a second lever 44.

Between said levers 44 there extends a wiper plate 45 which is adaptedto wipe material from the rake plate 42, when said rake mechanism 35 ispositioned adjacent the chute I9. The wiper plate 45 is biased to thenon-operating position illustrated in Fig. 4 by a pair of coil springs46, 46 associated with the levers 4| and 44.

Associated with each of the U-shaped guides 24, 24 is a cam 41,Which isadapted to tilt the rake mechanism 35 about the bolts 39 and to move thearms 4| from the position illustrated adjacent said cam at the bottom ofFig. 1 to a position in which said arms contact stop lugs 36. Thisprevents a sudden falling of the rake mechanism as it reaches the bottomof the channel l6, which, if allowed, would produce an undesirable shockupon the mechanism. This feature is disclosed and claimed in my abovementioned patent application, Serial No. 701,548.

Also associated with each of the U-shaped guides 24, 24 is a spring cam48 which is adapted to maintain resiliently an interleaving relationbetween the teeth 43 of the rake mechanism 35 and the screen l4. Thisconstruction is disclosed and claimed in my above mentioned application,

7 Serial No. 740,159.

.passes under said control box 49.

It is also to be noted that there is mounted upon a bracket I48 carriedby one of the U- shaped guides 24, 24 a control box 49 within which ishoused a pair of switches 56 and 5| (see Fig. '1) An operating lever 52is associated with said switches so that under normal conditions switch56 is closed and switch 5| is open. The lever 52 carries a roller 53adapted to be engaged by one of the plates 36 as rake mechanism 35 Itwill thus be evident that the switches 56 and 5| will be operatedwhenever rake mechanism 35 passes under the control box 49.

In the operation of the rake mechanism the plate 42 and teeth 43 willgather accumulated material on the screen l4 and carry it up the trough|8 until the chute i9 is reached. At this position upstanding levers 54,54 which are rigidly attached to the arms 44, 44, will engage stationarypins 55, 55 extending inwardly from the U-shaped guide plates 24, 24. Asa consequence, the levers 44, 44 will rock about the axis of bolts 39,39 and thus wipe from the rake plate 42 and teeth 43 any material orsewage which is carried-thereon,

forcing it to the chute 19 by which it is directed to hopper 26. Thisoperation is clearly illustrated by reference to Figs. 4 and 5 of thedrawings. The rake operating mechanism will continue until the plate 36engages roller 53 to 0p- 5 erate switches 56 and 5| in a manner whichwill be hereinafter described more in detail.

Associated with the hopper 26 and adjacent the top thereof is awaterspray 56 which will be operative to carry received material to thegrind- 1 er 2|. Spray 56 may take the form of a circumferential pipeprovided with a plurality of drilled apertures. This water spray isconnected to a source of water supply and is controlled by a solenoidoperated valve 51. The valve 51 is con- 15 trolled by solenoid 51' (Fig.'1) and operates at the same time the grinder motor 22 operates. Thegrinder will, of course, grind received material and discharge it as apulp into channel |6 through opening I22 in floor |3.

Attention is directed to Fig. '1 which illustrates the electricalcircuit for controlling the mechanism above described in detail. 66, 6|and 62 are powervmeans of a three phase power system which supply powerto the rake motor 36 and 25 the grinder motor 22, both of which may bethree phase induction type motors.

It is to be noted that associated with lines 66 and 6| and adjacent thegrinder motor 22 I provide a solenoid 51' which operates the water valve51 whereby water valve 51 will always be opened when the grinder motor22 is energized. As a consequence water will always be supplied to thehopper 26 when it is desired to grind any material, thus facilitatingthe grinding and keeping 85 the grinder clean and free of accumulatingsewage.' 1,

Associated with the grinder motor 22 is a magnetically operated switch63 by which said motor 22 is connected to the power mains 66, 6| and 62.4o

Said switch 63 is biased to normal open position and is closed wheneverthe operating coil 64 thereof is energized. Associated with said switch63 is a pilot switch 65 which controls certain control circuits, saidpilot' switch 65 being closed 45 whenever said switch 63 is closed.

Associated with the rake motor 36 I provide a magnetic switch 66, whichis the same construction as the switch 63, having an operating coil 61and a pilot switch 68. In the power mains 66, 6| and 62, leading to theswitch 66 I also provide a hand operated knife disconnecting switch 69.

The control means for said magnetic switches 63 and 66 comprises a handoperated knife switch 16, which, when in the position A provides forintermittent automatic operation of the system, as will be hereinafterdescribed, and. when in position B provides for continuous operation ofthe system.

In addition to the circuit connections for said control system I alsoprovide a pair of timing relays 1| and 12. It may be mentioned that therelay 1| is preferably of the typeknown commercially as the TSA-lOautomatic timer manufactured by The General Electric Company, which maybe constructed generally after the disclosure of the patent to Chester0. Hall, No. 1,483,443, dated February 12, 1924, except for certainminor obvious changes; and the relay 12 may be of the type commerciallyknown as the CR-2820-1699 70 definite time relay, manufactured by TheGeneral Electric Company, which may generally follow the disclosure ofthe patent to Hugh M. Stephenson, No. 1,699,125, dated January 15, 1929,

except for certain minor changes.

Briefly described, relay 1| comprises a small synchronous motor 13 whichdrives an operating pointer, which, after a predetermined adjustablemovement; will operate to close contacts 14 and maintain them closeduntil an electromagnetic clutch 15 is de energized, whereupon the abovementioned pointer will return to its normal zero position under theinfluence of a biasing spring. I haveprovided a pair of normally closedsafety contacts 16, along with a normally closed push button switch 11,in series with circuit of motor 13, said safety contacts 11 being openedin case the above mentioned pointer reaches its extreme position oftravel before the magnetic clutch 15 is de-energized. l

The relay 12, briefly described, comprises a synchronous motor 16, oneterminal'of whichis connected to an intermediate point on a solenoid 19,with which solenoid ;is associated an armature which controls a switch80. This relay is so constructed that upon energization of the solenoid19 the armature thereof will operate to engage gears, one'of which isdriven from the motor 18, and the other of which is connected to atiming cam which is biased to a zero position by a coil spring. When theengagement takes place between said gears and the motor 16 isuperated,.the cam rotates a predetermined variable amount until itrocks. a pivot lever 8| to'open contacts 82.

The operation of the control system will be evident from a descriptionof a typical cycle of movement of the rake mechanism with the consequentoperation of the grinder mechanism. Assume, for example, that it isdesired to operate the system automatically and it is desired to cleanthe screen I4 once every fifteen minutes, the switch 10 will be thrownto the position A, which is the automatic position, and the knife switch69 will be closed. Under these conditions a cir-, cuit will beestablished from power main 6| through conductor 83, overload cut-outswitch 84, conductor 35, overload cut-out switch 86, conductor 81 toterminal 86 of normally open switch thence over conductor 89, throughswitch 10, conductor 90 to terminal 9| of relay 1|. It is thus to benoted that terminal 9| of relay 1| is connected directly to power main6| through overload cut-out switches 64 and 86 whenever switch 10 is inposition A.

Power main 62 is connected directly to terminal 92 of relay 12 overconductor 93. Power from the main 62 is conducted from terminal 92 ofrelay 12 to terminal 94 of relay 1| over conductor 95. Between theterminals 9| and 94, which are thus connected respectively to mains 6|and 62, there is a circuit for the synchronous motor 13 which includesthe push button switch 11 and safety contacts 16, which circuit isobvious. In addition, a circuit is provided for the solenoid of magneticclutch from terminal 9| to terminal 92 by way of conductor 96, switch 56and conductor 91. Thus, to start the cycle of operation, magnetic clutch15 is energized and synchronous motor 13 starts to operate, therebymoving the above mentioned pointer so that after a predetermined timeinterval it will move to close contacts 14. A normal setting of thisrelay will be such that contacts 14 will be closed fifteen minutes aftermagnetic clutch 15 is energized. As a consequence, the screen |4 will becleaned and the grinder 2| will be set into operation. intermittentlyevery fifteen minutes. After the fifteen minute period has expired, theabove mentioned pointer will close contacts 14 of relay 1| moving therake along the guides 24, 24. Y

When magnetic switch 66 closed, it closed the contacts of switch 68which transfers power from the terminal 9| of relay 1| over conductorsI02 and I03 to terminal 14 of relay 12. Connected between the terminalsI04 and 92 of said relay 12 is solenoid 19, which is thus energized. At.

the same time the synchronous motor 18 of said relay 12 is energized.'As a consequence of the energization of solenoid 19, switch 80 will beclosed immediately transferring power from terminal I04 throughcontacts82, switch 80, conductor I06, operating coil 64, of magnetic switch 63and conductor N16 to terminal 92. As a conand a circuit will be closedfor operating coil 61 and the rake motor 30 starts tooperate, therebysequence, operating coil 64 will be energized, closing magnetic switch63 and starting the operation of grinder motor 22 and the opening of thewater valve 51. As a consequence the grinder will bestarting intooperation with water flowing into the hopper 20 ready to receive andgrind any sewage or refuse, and to discharge it as a pulp into thesewage stream. At the same time that solenoid 19 is energized, the motor18 of relay 12- started its operation, which, aftera predeterminedperiod, will result in the opening of con- The consequence of thisopening will tacts 82. be later described.

After the rake mechanism'has been set in motion by the rake motor 30with the grinder motor 22 operating the grinder 2| and the water valve51 opened as aforesaid, the rake mechanism will operate to delivermaterial to the Hopper 20 in the manner previously described. The rakemechanism will continue its operation until the plate 36 engages roller53 to rock arm 52, thereby to open the normally closed switch and'toclose the normally open switch"5|. When normally closed switch '50 isopened the previously traced circuit to the solenoid of magnetic clutch15will be broken. As a. consequence, the relay 1| will restore to itsnormal position and will begin a new time cycle as soon as said solenoidof magnetic clutch 15 is again operated. This will take placeimmediately because the rake continues to operate to a positionsuflicient to close the normally closed switch 56. This is insured byvirtue of the fact that when normally closed switch 50 opens normallyopen switch 5| closes, thus bridging the terminals 68 and 99 of saidswitch 5|. This insures that operating coil 61 will remain energizeduntil the rake motor moves the rake mechanism to a position to closeswitch 50 and open switch 5|.

chronous motor 16'ofsaid relay 12 starts to operi opened. This willbreak the previously traced tion thereof and the opening of the circuitleading to the operating coil N of magnetic switch 63, which will resultin the de-energizacircuit to grinder motor 22. As a consequence, relayI2 will restore to its normal position due to the fact that thepreviously mentioned circuit to said solenoid l9 and motor 18 is brokenby virtue oi the fact that switches and 68 are now both open. In thisconnection it is to be noted that switches 65 and 08 are connected inparallel over conductors I02, I01 and I00. As a consequence, when switch08 was opened upon the de-energization oi. operating coil 81, the relay1! was still energized over parallel switch 65 which had been closed inthe meantime, as previously described. It may also be mentioned that apush button switch I09 may be included in the circuit oi motor I8 ifdesired.

To operate the system continuously, which conditions the rake motor andthe solenoid are continuously operated, it is only necessary to move theswitch 10 to the position B. Under these conditions operating coil 61will be connected directly across the lines BI and 02 over obviouscircuits, including those previously traced, and from terminal 00,conductor -89, switch I0, conductor IIII, to coil 01.

under .-This insures. the continuous operation of rake parallel withoperating coil motor 30. Operating coil 04 will be connected in 01 overa circuit ineluding conductor 93, terminal 92, conductor coil 64,conductor I05, conductor III, switch 10, conductor H0, conductor 89, toterminal 00',

which, as previously described, is connected to main 6i.

It is thus seen that a system is provided whichwill screen a sewagestream of large particles of material, will automatically accumulatedmaterial and grind it, with water, to a pulp after which it is returnedto the stream.

' Due to this reduced condition the material can be easily handled bythe subsequent sewage treating mechanism. The entire system isautomatic,and may be operated intermittently, -or continuously, and when operatedintermittently the grinding apparatus will continue in operation for apredetermined period after the rake has been stopped. This insures acomplete grinding of. all material and, due to the supplying of water tothe grinder, insures that 'it will be thoroughly cleaned out after eachgrinding operation. 'I'his provides a new and improved method oftreating sewage to reduce to small particles any large particles in thesewage stream.

Obviously those skilled in the art may make various changes in thedetails and arrangement of parts without departing from the spirit andscope of the invention as defined by the claims hereto appended, and Itherefore wish not to be restricted-to the precise construction hereindisclosed.

Having thus described and shown an embodia when a predetermined motor,the grinder clean said screen oi combinasaid grinder and cleaning meansadapted to operate them periodically together and to continue theoperation of said grinder for a period after said cleaning means hasstopped. I

2, In liquid screening apparatus, the combin'ation wlth'a trough, of ascreen extending into said trough, a pivoted rake mechanism, means forguiding said rake mechanism acrosssaid screen to clean it, said rakemechanism comprising spaced parallel plates, a rake plate having teeth,levers pivotally connecting said plate to said plates, scraper mechanismfor said rake including levers also pivoted to said plates and a scraperplate extending therebetween, means for operating-said scraper mechanismto clean said rake position is reached by said rake mechanism, andresilient cam means for maintaining said rake mechanism in operativerelation with said screen.

3. In a liquid screening apparatus, the combination with a screenadapted to extend into a sewage stream, of a grinder, rake means forcleaning said screen of accumulated materials and delivering themimmediately to said grinder, means including said grinder adapted togrind said material and return it to said stream, means for supplyingwater to said grinder to aid in grinding said material, and controlmeans for operating said rake means,said grinder and said water supplymeans, said control means being constructed and arrangedflto operatesaid rake means, grinder and water supply means periodically togetherand to discontinue the operation of said rake means while prolonging theoperation of said grinder and water supply means.

4. In a liquid screening apparatus, the combination with a screenadapted to extend into a sewage stream, of rake means for cleaning saidscreen oi accumulated materials, a grinder adapted to be fed materialcleaned from said screen and to grind it and return it tosaid stream,

means for sup-plying water to said grinder to aid in grinding saidmaterial, and control means for a predetermined cycle and to start theoperation of said grinder and water supply means, and a secondtimingrelay constructed and arranged to prolong the operation supply meansafter said rake means is stopped.

5. Ina liquid screening apparatus, the combination with a screen adasewage stream, of rake means for cleaning said screen of accumulatedmaterials, a grinder adapted to be fed material cleaned from said screenand to grind it and return it to said stream, means for supplying waterto said grinder to aid in grinding said material, and control means foroperating said rake means, said of said grinder and water ted to extendinto a grinder and said water supply means, said control meanscomprising a first timing relay constructed and arranged to operate saidrake means periodically through a predetermined cycle and to start theoperation of said grinder and watersupply means, a sec-- 0nd timingrelay constructed and arranged to prolong the operation of said grinderand water supply means after said rake means is stopped, and means forrendering said timing relays inactive and operating said grinder, saidrake meansv and saidwater supply means continuously.

ROBERT E. BRIGGS.

